Lately, the electronic devices having the contact detection unit such as a touch sensor have been increasingly used for mobile terminals such as mobile phones. As a method to detect a contact by an operator, there are known variety of types, such as a resistive film type, a capacitive type, an optical type and the like. Those types detect the contact by a contact object such as an operator's finger, a stylus pen and the like.
As the electronic device having the contact detection unit, a touch panel having the contact detection unit and a display unit laminated to each other has been known. In the touch panel, the display unit is disposed on a rear face of the contact detection unit and displays graphical images of characters and images of buttons and the like (hereinafter, referred to as objects). When the operator presses the object displayed on the display unit, the contact detection unit detects a contact at a pushed position. A technique to provide a tactile sensation to the operator in response to pressing with a predetermined pressure load or higher has also been known.
Incidentally, some of the electronic devices display turned characters of authentication information input by the operator in user authentication. In this case, since the characters of the authentication information displayed are turned, the characters are not exposed to people around the operator and advantageous from a security standpoint. It has also been suggested to put a protective film on the display unit for preventing the characters of the authentication information from being exposed to people around the operator (for example, Japanese Patent Laid-Open No. 10-293644).
However, when the turned characters of the authentication information are displayed on the display unit, the operator himself/herself cannot read the characters, either. Therefore, it has been desired to provide an electronic device enabling the operator to confirm whether characters intended by the operator are acknowledged by a control unit.